Semiconductor wafers including die locations on their active surfaces may be relatively thin and brittle, lacking any substantial strength, particularly against bending stresses, which may result from the use of such wafers in processes to fabricate and encapsulate stacked multi-die semiconductor packages. To mechanically support a semiconductor wafer, which may be characterized as a “base wafer,” while individual semiconductor dice are stacked on these die locations to form multi-die semiconductor device assemblies, the semiconductor wafer may be attached to a carrier wafer or other physical support, for example, by positioning an attachment material, such as an adhesive, between the semiconductor wafer and the carrier wafer. Such a carrier wafer is also required due to the inability of wafer handling equipment to handle such a thin base wafer without damage. Subsequently, the active surface of the base wafer and laterally separated stacks of semiconductor dice thereon may be encapsulated in a protective material, for example, a dielectric molding material. After encapsulation, the carrier wafer may be detached from the semiconductor wafer. For example, the attachment material may be weakened by heating, and the semiconductor wafer and carrier wafer may be slid laterally relative to one another until the carrier wafer is removed. As another example, a laser may be used to heat and ablate the attachment material. As yet another example, a solvent may be used to dissolve portions of the attachment material, and the carrier wafer may be physically pulled away from the semiconductor wafer. Individual semiconductor device packages comprising the stacked, encapsulated semiconductor dice and a semiconductor die singulated from the semiconductor wafer may be formed by cutting through the protective material between the die stacks and through the semiconductor wafer along so-called “streets” between the die locations to “singulate” the semiconductor device packages from one another.
Such methods employing a carrier wafer supporting a base wafer can result in damage to the base wafer due to excessive wafer warpage resulting from the molding process employed to encapsulate a large number of die stacks on the base wafer. Further, debonding of a carrier wafer from the molded wafer assembly is costly and may also initiate damage. In addition, singulating the base wafer through the streets between die locations leaves semiconductor material exposed at the sides of the singulated die locations, and semiconductor material is also exposed at the side of the previously singulated semiconductor dice stacked on each die location prior to encapsulation by the dielectric molding material.